1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
use std::slice::Iter as SliceIter;
use std::time::Duration;
use crate::{Sample, Source};
#[derive(Clone)]
pub struct StaticSamplesBuffer<S>
where
S: 'static,
{
data: SliceIter<'static, S>,
channels: u16,
sample_rate: u32,
duration: Duration,
}
impl<S> StaticSamplesBuffer<S>
where
S: Sample,
{
pub fn new(channels: u16, sample_rate: u32, data: &'static [S]) -> StaticSamplesBuffer<S> {
assert!(channels != 0);
assert!(sample_rate != 0);
let duration_ns = 1_000_000_000u64.checked_mul(data.len() as u64).unwrap()
/ sample_rate as u64
/ channels as u64;
let duration = Duration::new(
duration_ns / 1_000_000_000,
(duration_ns % 1_000_000_000) as u32,
);
StaticSamplesBuffer {
data: data.iter(),
channels,
sample_rate,
duration,
}
}
}
impl<S> Source for StaticSamplesBuffer<S>
where
S: Sample,
{
#[inline]
fn current_frame_len(&self) -> Option<usize> {
None
}
#[inline]
fn channels(&self) -> u16 {
self.channels
}
#[inline]
fn sample_rate(&self) -> u32 {
self.sample_rate
}
#[inline]
fn total_duration(&self) -> Option<Duration> {
Some(self.duration)
}
}
impl<S> Iterator for StaticSamplesBuffer<S>
where
S: Sample + Clone,
{
type Item = S;
#[inline]
fn next(&mut self) -> Option<S> {
self.data.next().cloned()
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.data.size_hint()
}
}
#[cfg(test)]
mod tests {
use crate::source::Source;
use crate::static_buffer::StaticSamplesBuffer;
#[test]
fn basic() {
let _ = StaticSamplesBuffer::new(1, 44100, &[0i16, 0, 0, 0, 0, 0]);
}
#[test]
#[should_panic]
fn panic_if_zero_channels() {
StaticSamplesBuffer::new(0, 44100, &[0i16, 0, 0, 0, 0, 0]);
}
#[test]
#[should_panic]
fn panic_if_zero_sample_rate() {
StaticSamplesBuffer::new(1, 0, &[0i16, 0, 0, 0, 0, 0]);
}
#[test]
fn duration_basic() {
let buf = StaticSamplesBuffer::new(2, 2, &[0i16, 0, 0, 0, 0, 0]);
let dur = buf.total_duration().unwrap();
assert_eq!(dur.as_secs(), 1);
assert_eq!(dur.subsec_nanos(), 500_000_000);
}
#[test]
fn iteration() {
let mut buf = StaticSamplesBuffer::new(1, 44100, &[1i16, 2, 3, 4, 5, 6]);
assert_eq!(buf.next(), Some(1));
assert_eq!(buf.next(), Some(2));
assert_eq!(buf.next(), Some(3));
assert_eq!(buf.next(), Some(4));
assert_eq!(buf.next(), Some(5));
assert_eq!(buf.next(), Some(6));
assert_eq!(buf.next(), None);
}
}